695 research outputs found
Optimal control under uncertainty and Bayesian parameters adjustments
We propose a general framework for studying optimal impulse control problem
in the presence of uncertainty on the parameters. Given a prior on the
distribution of the unknown parameters, we explain how it should evolve
according to the classical Bayesian rule after each impulse. Taking these
progressive prior-adjustments into account, we characterize the optimal policy
through a quasi-variational parabolic equation, which can be solved
numerically. The derivation of the dynamic programming equation seems to be new
in this context. The main difficulty lies in the nature of the set of controls
which depends in a non trivial way on the initial data through the filtration
itself
Mechanistic lessons learned from studies of planktonic bacteria with metallic nanomaterials: implications for interactions between nanomaterials and biofilm bacteria
Metal and metal oxide nanoparticles (NPs) are used in numerous applications and have high likelihood of entering engineered and natural environmental systems. Careful assessment of the interaction of these NPs with bacteria, particularly biofilm bacteria, is necessary. This perspective discusses mechanisms of NP interaction with bacteria and identifies challenges in understanding NP-biofilm interaction, considering fundamental material attributes and inherent complexities of biofilm structure. The current literature is reviewed, both for planktonic bacteria and biofilms; future challenges and complexities are identified, both in light of the literature and a dataset on the toxicity of silver NPs toward planktonic and biofilm bacteria. This perspective aims to highlight the complexities in such studies and emphasizes the needs for systematic evaluation of NP-biofilm interaction
The Higgs Sector of the Minimal 3 3 1 Model Revisited
The mass spectrum and the eigenstates of the Higgs sector of the minimal 3 3
1 model are revisited in detail. There are discrepancies between our results
and previous results by another author.Comment: 20 pages, latex, two figures. One note and one reference are adde
Contributions of rotation, expansion and line broadening to the morpho-kinematics of the inner CSE of oxygen-rich AGB star R Hya
We use archival ALMA observations of the CO(2-1) and SiO(5-4) molecular line
emissions of AGB star R Hya to illustrate the relative contributions of
rotation, expansion and line broadening to the morpho-kinematics of the
circumstellar envelope (CSE) within some ~0.5 arcsec from the centre of the
star. We give evidence for rotation and important line broadening to dominate
the inner region, within ~100 mas from the centre of the star. The former is
about an axis that projects a few degrees west of north and has a projected
rotation velocity of a few km/s. The latter occurs within some 50-100 mas from
the centre of the star, the line width reaching two to three times its value
outside this region. We suggest that it is caused by shocks induced by stellar
pulsations and convective cell ejections. We show the importance of properly
accounting for the observed line broadening when discussing rotation and
evaluating the radial dependence of the rotation velocity.Comment: 8 pages, 8 figure
Petrographic Characteristics and Depositional Environment Evolution of Middle Miocene Sediments in the Thien Ung - Mang Cau Structure of Nam Con Son Basin
This paper introduces the petrographic characteristics and depositional environment of Middle Miocene rocks of the Thien Ung - Mang Cau structure in the central area of Nam Con Son Basin based on the results of analyzing thin sections and structural characteristics of core samples. Middle Miocene sedimentary rocks in the studied area can be divided into three groups: (1) Group of terrigenous rocks comprising greywacke sandstone, arkosic sandstone, lithic-quartz sandstone, greywacke-lithic sandstone, oligomictic siltstone, and bitumenous claystone; (2) Group of carbonate rocks comprising dolomitic limestone and bituminous limestone; (3) Mixed group comprising calcareous sandstone, calcarinate sandstone, arenaceous limestone, calcareous claystone, calcareous silty claystone, dolomitic limestone containing silt, and bitumen. The depositional environment is expressed through petrographic characteristics and structure of the sedimentary rocks in core samples. The greywacke and arkosic sandstones are of medium grain size, poor sorting and roundness, and siliceous cement characterizing the alluvial and estuarine fan environment expressed by massive structure of core samples. The mixed calcareous limestone, arenaceous dolomitic limestone, and calcareous and bituminous clayey siltstone in the core samples are of turbulent flow structure characterizing shallow bay environment with the action of bottom currents. The dolomitic limestones are of relatively homogeneous, of microgranular and fine-granular texture, precipitated in a weakly reducing, semi-closed, and relatively calm bay environment
An increased proportion of transgenic plants in the progeny of rapeseed (<i>Brassica napus</i> L.) transformants
Cotyledon and leaf explants of two spring rapeseed varieties were transformed with Agrobacterium tumefaciens harboring a genetic construct with the gfp marker gene. In order to reduce the proportion of hyperhydrated shoots, which appeared during regenerant formation, we optimized sucrose content in the regeneration media. Analysis of the progeny obtained from T0 regenerants showed that in a number of lines the distribution of the gfp marker did not follow Mendelian segregation of a monogenic trait in self-pollinated plants, while in the progeny of the other lines of transgenic plants, the gfp marker was completely absent, although its presence had been confirmed in all selected T0 plants. We also found that in individual transformants gfp is randomly inherited throughout the central peduncle; its presence in the genome of seedlings does not depend on the location of the pod. Thus, both transformed and non-transformed cells were involved in the formation of gametes in T0 plants. In addition, marker segregation was different in plants of the T1 line obtained by nodal cuttings of a primary transformant, depending on the location of the cuttings on the stem of the original plant, indicating that the nature of T1 generation plants was also chimeric. Furthermore, we showed that propagation of plants by cutting followed by propagation by seeds formed as a result of self-pollination led to an increase in the proportion of transgenic plants in subsequent generations. The results obtained during the course of this study show that the transformants were chimeric, i. e. their tissues contained both transgenic and non-transgenic cells, and this chimeric nature was passed on to subsequent generations. We found that, in addition to nutrient media composition, other factors such as plant genotype and explant type also contribute to the rising of chimeric plants during transformation. Based on these results, we developed a simplified method, which consists of several rounds of a combination of cutting, seed production by self-pollination, and subsequent culling of wild-type plants, which significantly enriched descendent populations of the original rapeseed transformants with plants transgenic for the gfp marker
L^{2}-restriction bounds for eigenfunctions along curves in the quantum completely integrable case
We show that for a quantum completely integrable system in two dimensions,the
-normalized joint eigenfunctions of the commuting semiclassical
pseudodifferential operators satisfy restriction bounds ofthe form for generic
curves on the surface. We also prove that the maximal restriction
bounds of Burq-Gerard-Tzvetkov are always attained for certain exceptional
subsequences of eigenfunctions.Comment: Correct some typos and added some more detail in section
Assessing the Impact of Innovative Technologies on the Life Satisfaction of Older Adults in Russia and Vietnam
Received 4 April 2023. Accepted 8 August 2023. Published online 6 October 2023.This study uses the concept of “technological space,” a term that defines the interplay between the social and technological environment, extending our understanding of environmental factors in various scientific domains. We examine the significance of technological space by looking at how older adults interact with modern technologies in the regional contexts of Russia and Vietnam. This study is motivated by the need to integrate older adults into the regional technological landscape. Although older adults face various challenges that may prevent them from adopting modern technologies in their daily lives, embracing these high-tech products and services can greatly improve their overall happiness and well-being. The analysis draws upon the data gathered
through a sociological study in Russia’s Tomsk region and a parallel study conducted in Vietnam in 2022. The research outcomes show a noticeable contrast in older individuals’ readiness to embrace innovative technologies, highlighting their openness to adaptation under specific circumstances. Additionally, these findings underscore the limited and varied extent to which older generations engage with the contemporary regional technological space, as well as the constrained impact of innovative technology on their life satisfaction. These findings can be useful for regional policymakers seeking to enhance the adaptability of older adults in the face of socio-economic challenges.The study was supported by the Russian Science Foundation, project No. 19-18-00300, https://rscf.ru/project/19-18-00300/
- …